The creation of the two prototypes was sponsored by Khaled. This first prototype was a miserable failure. The 2x2x2 turning was fine, but the gearing was completely jammed. The second prototypes had two improvements. First of all, the numbered pieces are now well confined in a rails mechanism. Secondly, the numbered pieces are centered around a circle, as was suggested by Khaled. The result is a puzzle that turns much better than Khaled and I could have dreamed.